When plating articles with a plating solution containing metals, the plated articles are typically removed from the plating solution and dipped into one or more rinse water tanks to effect removal of excess plating material so as to improve the quality of the plated finish. The rinse water tanks gradually accumulate therein various plating metals such as zinc, nickel, silver, gold or tin, depending upon the plating material. The metals which collect in the rinse water tanks ultimately reach a concentration level which requires disposal of the rinse water, the latter commonly being referred to as waste water. The waste water is typically treated in an attempt to remove heavy metals since disposal of the waste water creates a pollution problem. For this reason, numerous processes and apparatus have been developed for treating the waste water, including arrangements which involve a plurality of large electrically charged plates which are contained in a waste water treating tank so as to effect electrolytic deposit of the metals on the plates, which plates are then removed and either cleaned for reuse or otherwise properly disposed of. Most known processes and apparatus for treating waste water, however, have been structurally complex and costly, and in many situations wholly unsuitable for use in smaller business operations where the cost and/or operational magnitude of the arrangement makes use of such apparatus uneconomical.
Accordingly, it is an object of this invention to provide an improved apparatus for treating plating waste water, particularly for removing metals from the waste water, which apparatus is structurally simple and economical, which operates in a highly desirable manner, and which is particularly suitable for use by small businesses.
More specifically, the improved waste water treating apparatus of this invention involves a tank which defines therein an interior treating chamber. A sleevelike electrode which functions as an anode is positioned concentrically within and spaced slightly from the tank wall. An electrode which functions as a cathode is concentrically positioned within and spaced from the anode, with the cathode being defined by two or more concentric but slightly spaced coil springs, with at least the outer spring functioning to receive thereon the metal deposits. In this improved apparatus, a diffuser plate is provided at one end of the treating chamber and associated with the waste water inlet so as to control flow into the treating chamber. The apparatus is preferably operated under a condition whereby the chamber is maintained under a low pressure, such as about one atmosphere pressure.
Other objects and purposes of the invention will be apparent to persons familiar with devices of this general type upon reading the following specification and inspecting the accompanying drawings.